The present invention generally relates to the art of toothbrushes, and more specifically to a toothbrush which can effectively clean three exposed surfaces of the teeth simultaneously, and the method of making such toothbrushes.
There have been proposed numerous toothbrushes which are intended to provide cleaning surfaces that conform to the shape of the teeth. The object of all of these toothbrushes is to permit effective cleaning of all three exposed surfaces of the teeth simultaneously, namely the labial, lingual or palatal, and cutting and masticating surfaces. While many proposed solutions have been offered, very few have been implemented either because they are not commercially feasible, or impractical in their use.
There have been known, for example, toothbrushes which are provided with V-shaped heads providing two generally planar surfaces which form therebetween a predetermined angle of less than 180.degree.. The bristles are mounted on these surfaces and are directed inwardly towards each other at a predetermined angle. Typical constructions of this type are shown and described in the following patents: French Pat. No. 1,164,294; Australian Pat. No. 212,559; French Pat. No. 707,843; British Pat. No. 366,382; Swiss Pat. No. 150,573; and U.S. Pat. Nos. 569,870 and 2,807,820. Similar toothbrushes having cylindrical or square configurations, instead of V-shaped head portions, are shown and described in U.S. Pat. Nos. 1,118,156; 2,077,392; and 2,090,663. However, the aforementioned toothbrushes have not been practical to manufacture because of the difficulty in molding the brush in its final configuration with the bristles in place. Heretofore, when molding a brush with the bristles in place, it was necessary to mold the brush in a flat shape and a secondary operation was required in order to curve the head portion so as to bring the two bristle sections into opposing position. Thus, while two-headed brushes have long been known in the art, their commercial exploitations have been unsuccessful.
Other toothbrushes have been proposed which suggest the use of removable bristle elements from the main toothbrush body or support member. For example, in U.S. Pat. No. 1,189,505, a toothbrush is described wherein the opposing bristle pads are disposed on opposite sides of each other and the bristles are oriented parallel to each other. The configuration and the size of the toothbrush disclosed as well as the other complexities inherent in the toothbrush make it extremely impractical, expensive and inconvenient to use. Removable bristle pads or elements are also disclosed in U.S. Pat. Nos. 2,674,000; 2,622,260; and 2,323,623. These last three mentioned patents disclose conventional toothbrushes with removable bristle pad elements, although U.S. Pat. No. 2,674,000 further includes means for dispensing toothpaste. Removable brush elements are also disclosed in U.S. Pat. Nos. 2,093,383 and 2,736,917, the first mentioned patent disclosing a generally U-shaped head portion with removable lateral sides. However, the above-described toothbrushes which have removable bristle elements are generally complex in construction and, therefore, expensive to manufacture. Additionally, toothbrushes having V-shaped head portions have not been provided with removable bristle pads and, for reasons stated above, have not been commercially exploited.
Other miscellaneous toothbrush constructions are described in U.S. Pat. Nos. 1,830,995; 1,976,271; 2,232,269; and 2,685,703. However, none of these last mentioned patents nor the patents mentioned above describe or suggest a toothbrush with a generally V-shaped head portion which is practical to use, and simple and economical to manufacture.